A Portable Multi-sensor Navigation System for In-vehicle and On-foot Navigations

摘要

Global Positioning System (GPS) is commonly used for navigation which requires direct line of sights to at least four satellites. The direct line of sight requirement cannot be fulfilled in portable navigation systems (PNS) operation environments due to the unavailability of the GPS signals for certain situations such as indoors. Therefore, a PNS should incorporate some other navigation sensors for uninterrupted navigation solution. Ideally, the navigation sensors for PNS should be autonomous, compact, low-power consuming, low cost, drift free and indifferent to the external environmental factors. For a practical PNS, Micro Electro Mechanical System (MEMS) sensors can satisfy some of these requirements. This paper introduces a PNS that integrates MEMS accelerometers, gyros and magnetometer sensors with GPS to provide uninterrupted navigation solution to the user. The PNS is designed to provide continuous navigation information to a user despite of the mode of transit, i.e., whether the user is on-foot or in-vehicle. The navigation equations for the two modes of transits are completely different and therefore, it is the first step for the PNS software to be able to detect the respective mode of transit of the user. After mode identification, the PNS software can choose the appropriate navigation equations. This paper provides a software switch to detect the mode of transit and the results from in-vehicle and on-foot modes of transit.